1. Field of the Invention
The present invention relates to a propeller shaft and a constant velocity universal joint used therein, which are used in wheeled motor vehicles.
2. Description of the Related Art
Usually, the propeller shaft for the wheeled motor vehicle has a split construction including a drive shaft that is adapted to connect to an output shaft of a transmission, a driven shaft that is adapted to connect to a differential gear and a coupling device, such as, constant velocity universal joint, Cardin joint or the like, that is operatively disposed between mutually facing ends of the drive and driven shafts. In practical use, an axially middle portion of the propeller shaft is rotatably held by a support device fixed to a body of the vehicle. Furthermore, for holding a grease in the coupling device, there is provided a boot between the drive shaft and the coupling device.
One of such boots is disclosed by U.S. Pat. No. 7,470,198. The boot disclosed by the patent is generally conical in shape and made of a soft rubber or flexible plastic. A larger diameter outer portion of the boot is secured to an outer cylindrical member of a constant velocity universal joint (viz., coupling device) through an annular metal retainer and a smaller diameter inner portion of the boot is secured to the drive shaft through an annular metal band. With provision of the boot, an interior of the constant velocity universal joint is protected from entry of muddy water, dusts and the like and furthermore a grease in the interior is suppressed from leakage.